import {Vector3} from "../../build/three.module.js";

var GeometryUtils = {

    /**
     * Generates 2D-Coordinates in a very fast way.
     *
     * Based on work by:
     * @link http://www.openprocessing.org/sketch/15493
     *
     * @param center     Center of Hilbert curve.
     * @param size       Total width of Hilbert curve.
     * @param iterations Number of subdivisions.
     * @param v0         Corner index -X, -Z.
     * @param v1         Corner index -X, +Z.
     * @param v2         Corner index +X, +Z.
     * @param v3         Corner index +X, -Z.
     */
    hilbert2D: function (center, size, iterations, v0, v1, v2, v3) {

        // Default Vars
        var center = center !== undefined ? center : new Vector3(0, 0, 0),
            size = size !== undefined ? size : 10,
            half = size / 2,
            iterations = iterations !== undefined ? iterations : 1,
            v0 = v0 !== undefined ? v0 : 0,
            v1 = v1 !== undefined ? v1 : 1,
            v2 = v2 !== undefined ? v2 : 2,
            v3 = v3 !== undefined ? v3 : 3
        ;

        var vec_s = [
            new Vector3(center.x - half, center.y, center.z - half),
            new Vector3(center.x - half, center.y, center.z + half),
            new Vector3(center.x + half, center.y, center.z + half),
            new Vector3(center.x + half, center.y, center.z - half)
        ];

        var vec = [
            vec_s[v0],
            vec_s[v1],
            vec_s[v2],
            vec_s[v3]
        ];

        // Recurse iterations
        if (0 <= --iterations) {

            var tmp = [];

            Array.prototype.push.apply(tmp, GeometryUtils.hilbert2D(vec[0], half, iterations, v0, v3, v2, v1));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert2D(vec[1], half, iterations, v0, v1, v2, v3));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert2D(vec[2], half, iterations, v0, v1, v2, v3));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert2D(vec[3], half, iterations, v2, v1, v0, v3));

            // Return recursive call
            return tmp;

        }

        // Return complete Hilbert Curve.
        return vec;

    },

    /**
     * Generates 3D-Coordinates in a very fast way.
     *
     * Based on work by:
     * @link http://www.openprocessing.org/visuals/?visualID=15599
     *
     * @param center     Center of Hilbert curve.
     * @param size       Total width of Hilbert curve.
     * @param iterations Number of subdivisions.
     * @param v0         Corner index -X, +Y, -Z.
     * @param v1         Corner index -X, +Y, +Z.
     * @param v2         Corner index -X, -Y, +Z.
     * @param v3         Corner index -X, -Y, -Z.
     * @param v4         Corner index +X, -Y, -Z.
     * @param v5         Corner index +X, -Y, +Z.
     * @param v6         Corner index +X, +Y, +Z.
     * @param v7         Corner index +X, +Y, -Z.
     */
    hilbert3D: function (center, size, iterations, v0, v1, v2, v3, v4, v5, v6, v7) {

        // Default Vars
        var center = center !== undefined ? center : new Vector3(0, 0, 0),
            size = size !== undefined ? size : 10,
            half = size / 2,
            iterations = iterations !== undefined ? iterations : 1,
            v0 = v0 !== undefined ? v0 : 0,
            v1 = v1 !== undefined ? v1 : 1,
            v2 = v2 !== undefined ? v2 : 2,
            v3 = v3 !== undefined ? v3 : 3,
            v4 = v4 !== undefined ? v4 : 4,
            v5 = v5 !== undefined ? v5 : 5,
            v6 = v6 !== undefined ? v6 : 6,
            v7 = v7 !== undefined ? v7 : 7
        ;

        var vec_s = [
            new Vector3(center.x - half, center.y + half, center.z - half),
            new Vector3(center.x - half, center.y + half, center.z + half),
            new Vector3(center.x - half, center.y - half, center.z + half),
            new Vector3(center.x - half, center.y - half, center.z - half),
            new Vector3(center.x + half, center.y - half, center.z - half),
            new Vector3(center.x + half, center.y - half, center.z + half),
            new Vector3(center.x + half, center.y + half, center.z + half),
            new Vector3(center.x + half, center.y + half, center.z - half)
        ];

        var vec = [
            vec_s[v0],
            vec_s[v1],
            vec_s[v2],
            vec_s[v3],
            vec_s[v4],
            vec_s[v5],
            vec_s[v6],
            vec_s[v7]
        ];

        // Recurse iterations
        if (--iterations >= 0) {

            var tmp = [];

            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[0], half, iterations, v0, v3, v4, v7, v6, v5, v2, v1));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[1], half, iterations, v0, v7, v6, v1, v2, v5, v4, v3));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[2], half, iterations, v0, v7, v6, v1, v2, v5, v4, v3));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[3], half, iterations, v2, v3, v0, v1, v6, v7, v4, v5));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[4], half, iterations, v2, v3, v0, v1, v6, v7, v4, v5));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[5], half, iterations, v4, v3, v2, v5, v6, v1, v0, v7));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[6], half, iterations, v4, v3, v2, v5, v6, v1, v0, v7));
            Array.prototype.push.apply(tmp, GeometryUtils.hilbert3D(vec[7], half, iterations, v6, v5, v2, v1, v0, v3, v4, v7));

            // Return recursive call
            return tmp;

        }

        // Return complete Hilbert Curve.
        return vec;

    }

};

export {GeometryUtils};